1. Field to which the Invention Relates
When conventional sailboats, be they yawls or yachts, are sailed close to the wind, the wind pressure causes the mast to lean to leeward. The rigid connection between mast and hull causes the boat to heel. To counteract the torque applied to the mast and therefore to the hull with a corresponding torque in the opposite direction, the load, i.e. the crew, is shifted to windward. On larger boats such as yachts the keel also contributes to this counteracting torque. Despite these counteractive torques, however, the conventional sailing technique allows the mast to be inclined to leeward and it also allows the hull to heel over.
The technique of windsurfing with a sailboat differs from the conventional sailing technique in that the mast is inclined to luff, i.e. to the windward side, rather than to leeward. A precondition for application of the windsurfing technique is that the mast be free to incline in any direction, i.e. not only sideways but also for and aft.
The present invention makes it possible
first, to counteract the torque caused by the wind pressure and acting on the mast with a torque of the same magnitude in the opposite direction,
second, to prevent the transmission of torques to the hull, and
third, to shift the mast in any desired direction and hence to the particular position required for sailing according to the windsurfing technique.
2. Description of the Prior Art
People have been trying to counteract the heel of sailboats in various ways for a long time. One way is to use a heavier keel that is joined rigidly to the hull, and the weight of which reduces the boat's heel. Mechanisms are also known with which the boat's cargo or weights carried specifically for the purpose in the hull can be shifted to windward. It is common sailing practice to position the crew on the windward side of the boat. The crew's weight can be utilized even better by leaning out on trapeze rigging. In the case of catamarans, an even greater torque can be produced to counteract that acting on the mast because the crew is positioned on the windward side with a longer lever arm.
U.S. Pat. No. 3,985,106 describes a system that enables the mast to be inclined a few degrees out of the vertical to leeward to a limited angle around the boat's fore-aft axis. Corresponding to this inclination, the keel is swung out to the opposite side, the windward side. As a result, the heel of the boat's hull can be counteracted somewhat more than usual.
U.S. Pat. No. 4,094,263 describes a similar system. Here again the mast can be inclined in a plane at right angles to the boat's fore-aft axis. The maximum possible inclination angle of the mast to leeward is greater than in the case of U.S. Pat. No. 3,985,106, but it remains restricted because of the connection with the movable keel. With this system, too, the keel swings to windward in order to increase the pull-back torque on the mast, which is being forced to leeward by the pressure of the wind.
U.S. Pat. No. 4,117,797 is largely similar to U.S. Pat. No. 4,094,263. In addition to a mechanical tackle connection between inclinable mast and inclinable keel, however, it also proposes a hydraulic system for moving mast and keel. But the system continues to pursue the purpose of swinging the keel out to windward when sailing close to the wind, i.e. in opposition to the inclination of the mast, in order to reduce the heel of the boat's hull.
France Pat. No. 2,323,574 describes another similar system with which the mast can be inclined in a plane at right angles to the boat's fore-aft axis. Once again the proposed mechanism pursues the purpose of swinging the keel out in the direction opposite to the mast's inclination.
All of the aforementioned designs are based on conventional sailing technique, namely allowing the sail and mast to tilt to leeward when sailing close to the wind. Accordingly, the crew, cargo and keel weights are shifted as far as possible to windward in order to keep the mast upright. Some designs employ a mast that can be inclined sideways at a restricted angle in the plane that lies at right angles to the boat's fore-aft axis. No patent refers to a mast foot support permitting unrestricted inclination in any direction.
Apart from this state of the art in boatbuilding, there is also a state of the art in the construction of sailboards. Here a mast foot allowing unrestricted inclination of the mast in any direction is a known design feature. But this rotating mast foot is mounted on a sailboard, not on a boat's hull. The windsurfing principle is not transferable to sailing devices such as sailboats with greater sail area, because the weight of the human body is insufficient to counteract the wind power effected on larger sails.
3. Description of the New Knowledge
In contrast to the described traditional sailing technique, in which the mast and sail tilt to leeward by the force of the wind, the technique of sailing a windsurfing sailbaord demonstrates that a converse type of sailing is possible as well. In windsurfing, the mast and sail are pulled to windward. This produces advantages in comparison with the old sailing technique. The purpose of the present invention is to transfer these advantages of the mast and sail position in windsurfing to a sailboat (yawl or yacht) and to construct a system with which the mast of a sailboat can be inclined to windward and held there. It is surprising to note that such systems do not exist.
What is new is that the sailboat mast, like that of a sailboard, is supported in a mast foot that allows the mast to be inclined in any direction. It is not enough simply to support the mast in a hinge joint. In contrast to the previous systems with inclinable masts, which allow the mast to tilt only in a single plane lying at right angles to the hull's fore-aft axis, the invention proposes for the first time that the mast of yawls and yachts be supported to allow unrestricted inclination in any direction.
Also new is the proposal that, in contrast to windsurfing equipment, a weight or "dolphin" be used in addition. This "dolphin" is a new element that has never been used in conjunction with sailboats or sailboards in the past. The dolphin is neither a keel nor a centreboard. It is still necessary to fit a keel or centreboard to the boat's hull.
It is also new that a sailboat build according to the new system consists of three parts, namely: 1. of a hull with keel or centreboard; 2. of a mast that is, with respect to the hull, freely inclinable in any direction; and 3. of a "dolphin", which is movable to port or starboard as well as to the bow or the stern.
It is also new that the opposing force to the force of the wind acting on the sail is produced by the dolphin and that, because of this, the hull remains unaffected by the rotation of the mast.
Finally, it is new that this system makes it possible to sail a sailing device larger than a sailboard (i.e. a sailboat) using the windsurfing technique.